Manus Boonjumnong (Thai: มนัส บุญจำนงค์; RTGS: Manat Bunchamnong, born June 23, 1980) is a Thai boxer who won the Olympics at Light Welterweight (60–64 kg) at the 2004 Summer Olympics. He is the older brother of Non Boonjumnong.

At the 2003 World Amateur Boxing Championships in his home town Bangkok, the light-footed counterpuncher won the bronze medal losing to Russian Alexander Maletin.

In 2006, he made a successful comeback when he was crowned Asian champion. He narrowly defeated reigning 2005 world champion Serik Sapiyev at the tournament although he was knocked down.

In Chicago at the 2007 World Amateur Boxing Championships, he was upset early against Japanese Masatsugu Kawachi.

Boonjumnong qualified for the Athens Games by ending up in first place at the 1st AIBA Asian 2004 Olympic Qualifying Tournament in Guangzhou, PR China. In the final he defeated Kazakhstan's Nurzhan Karimzhanov. In Athens he beat reigning world champion Willy Blain and the Cuban Yudel Johnson in the final and won gold.
2004 Olympic Results

• Defeated Spyridon Ioannidis (Greece) 28:16
• Defeated Romeo Brin (Philippines) 29:15
• Defeated Willy Blain (France) 20:8
• Defeated Ionut Gheorghe (Romania) 30:9
• Defeated Yudel Johnson (Cuba) 17:11

• Defeated Masatsugu Kawachi (Japan) 8:1
• Defeated Serik Sapiyev (Kazakhstan) 7:5
• Defeated Roniel Iglesias Sotolongo (Cuba) 10:5
• Lost to Manuel Félix Díaz (Dominican Rep.) 12:4^[2][3]

Result	Record	Opponent	Type	Round, time	Date	Location	Notes
Loss	5–1	Ryan Ford	TKO	5 (8)	April 22, 2016	7th Infantry Division, Mae Rim, Chiang Mai, Thailand
Win	5–0	David Saul	TKO	5 (8)	March 25, 2016	Pa Bon, Thailand
Win	4–0	Suik Haidari	TKO	3 (8)	January 22, 2016	Wat Phraboromthat Chaiya, Surat Thani, Thailand
Win	3–0	Jonatan Simamora	KO	1 (6)	December 7, 2015	Hua Hin Center, Hua Hin, Thailand
Win	2–0	Marco Tuhumury	UD	4	September 27, 2015	Central Plaza Westgate Department Store, Bangkok, Thailand
Win	1–0	Jamed Jalarante	UD	4	June 27, 2015	Hua Mark Indoor Stadium, Bangkok, Thailand	Professional boxing debut.

• Boxing record for Manus Boonjumnong from BoxRec (registration required)
• Manus Boonjumnong at databaseOlympics.com